Collapsible hollow form for concrete-construction work.



E. M. CAMP.

COLLAPSIBLE HOLLOW FORM FOR CONCRETE CONSTRUCTION WORK.

APPLICATION FILED FEB. 29. 1916.

1,204,936. Patented Nov. 14, 1916.

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E. M. CAMP.

COLLAPSIBLE HOLLOW FORM FOR CONCRETE CONSTRUCTION WORK.

APPLICATlON FILED FEB. 29. 1916.

1,204,936. Patented Nov. 14,1916.

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ERVIN M. CAMP, 01? DENVER, COLORADO.

COLLAPSIBLE HOLLOW FORM FOR CONCRETE-CONSTRUCTION WORK.

Specificationof Letters Patent.

Patented Nov. 14, 1916.

Application filed February 29, 1916. Serial No. 81,157.

To a whom it may concern Be it known that I, 'EnvIN M. CAMP, a citizen of the United Statesof America, residing in the city and county of Denver and State of Colorado, have invented a new and useful Collapsible Hollow Form for Concrete-Construction Fork, of which the following is a specification.

My invention relates to a new type of collapsible hollow or tubular concrete construction work concrete mortar holding form for the construction of concrete, plaster or like material, and for constructing tubular concrete work and for covering columns and beams in steel building construction, and for other uses, and the objects of my invention are: .First, to provide a double trussed type of concrete mortar holding and molding form that is composed of an inner and an outer sectional part which trussingly support each other rigidly in a predetermined rela tion to each other. Second, to provide a collapsible concrete mortar holding and concrete molding form in which the outer sectional parts of the form are easily removed from the inner sectional part, and the inner sectional part is easily and quickly removed from the molded concrete form after it has hardened. Third, to provide a sectional concrete mortar holding and concrete molding type of form, in which two or more lengths of the form are attachably and releasably secured together in end to end alinement with each other, and after one form is poured with mortar concrete and the concrete has set, the outer and inner sections of the form are removed and they are secured to the opposite end of another form. Consequently the forms can be set up in intermittent, progressive and substantial contin uous pouring and filling order. I attain these objects by the mechanism illustrated in the accompanying drawings, in which:

Figure 1, is a. perspective view of the improved collapsible concrete-holding form. Fig. 2, is a vertical, transverse sectional view thereof. Fig. 3, is a central horizontal sectional view of the same. Fig. 4, is an under side plan view of the detachable section of the inner tubular member of the form; Fig. 5, is an end view, showing the arrangement of the form when two parallel inner tubular members are employed. Figs. 6, 7 and 8, are diagrammatic views illustrating various styles of inner tubular members which are 7 contemplated in the invention. And Fig.

.maining figures of the drawings the numeral 1 designatestheinner member of my improved concrete molding form, which hereinafter I will call the tubular member of the form. This tubular member of my form is composed of three pieces, 2, 3 and 4. The two pieces 2 and 3 are arcs of sli 'htly' less length than together would form the full circle of this tubular member of the form,

and the intervening space is filled by the curved segment piece 4, which is removably secured to them by any suitable means, but

preferably in the following manner: The inside surface of, the segment piece 4, as well as of the two larger sections, may be provided with stiffening bars or trussing ribs and 6 respectively, which are preferably in the form of angle bars, one limb of which is riveted or otherwise secured to the inner surface of the section and the other limb projects inwardly from the inner surface of the bar. On all of the segments of the inner tubular form these angled truss 'or stiffening members are positioned at a short distance from the opposite ends of the length of the form, which would be sufficient for small forms for small pipes and for small work. When, however, forms are made for pipes of large diameter and for large work, and especially for long forms of from five to ten feet in length, they should be provided with these inner truss members at suitable intervals apart throughout" their lengths. The end stiffeners of all of the segments are preferably positioned in alinement with each other to permit the flat ends of curved plates 7 which are secured to the angle bars of the segment 4, and which are extended beyond the side edges of this section 4, to extend over and be secured to the fiat limbs of the adjacent stiffening angle bars of the segments 2 and 3, by threaded pins 8, that extend through apertures in the segments 2' and 3, and into threaded apertures in the extended ends of the plates 7, as clearly Consequently this closshown by Fig. 2. ing gap section 4, is securely but detachably secured to the segments 2 and 3, by the pins 8, which extend through the outer sections of the form, as will be presently described.

The two segments 2 and 3, are hinged together at their lower meeting ends by any form of hinge, but a common form of pin and eye hinge 9 is shown. These hinges are formed preferably with the eyes projecting inwardly from the inner surfaces of the segments, the two eyes of each hinge being positioned side by side and in alinement with each other and the pin passing through both of them, and each eye is provided with a tongue portion, one of which is secured to one of the segments, and the other to the opposite segment. This arrangement brings the hinges within the tubular section and leaves the outside surface of the tubular section smooth and free of projections and at the same time permits the two hinged segments to be folded inwardly until their side edges meet after the segment a has been withdrawn. This collapsible feature of the inner tubular section permits it to be quickly and easily withdrawn from a molded concrete member after it has set and hardened sufliciently to permit the tube to he withdrawn without disarranging the concrete. I preferably use four of these hinges in the length of the section, but more may be used if desired. This inner tubular section is detachably secured to the outer sectional parts of my concrete molding form. This outer portion I term the casing 10 of the form. These casings 10 are arranged and adapted to stand at such a predetermined distance from the tube as is necessary to secure the desired thickness of concrete wanted around the tube for the work being done, and by using threaded gaging pins 8, of different lengths, the width of this space can be increased or diminished as desired, which, of course, would increase or diminish the thickness of the concrete around the tube. In the drawings, I have illustrated the most generally used distance apart of the casing and the tube for general pipe covering or for round hole molding concrete work. These casings 10 comprise two independent but similarly constructed members whichare interchangeable from one sideto the other of the tube. They are each preferably made to stand substantially in a vertical plane from their lower ends to even with the horizontal plane of the inner tube, being made this way in order that they may rest on a wooden or metal form below a pipeand so that they can be placed on the ground and will standerec't and will support the inner tube firmly against accidental lateral displacement from their set position. These casingsare made long enough to extend the same distance or ,a little farther than the same distance below the bottom of the tube that the casing members are placed holes of the tube 13.

from the opposite sides of the tube. From the center of the tube these two independent side casings are curved to extend in a con centric circle around the tube and at a predetermined distance from its outside surface that is sufficient to form a concrete casting of the desired thickness between the tube and the inside surface of the casings, which distance is determined by the gaging and the trussing and supporting pins 8, as will i be presentlv described. These sheet iron casings are reinforced by right angled bars 12, which are positioned at their ends and at positions opposite to the angle bars of the inner tube. I illustrate only four angle bars, but more of them may be used if desired, between the inner angle bars. top and the bottom edges of these casings are also provided with and reinforced by angle bars '13. All of these angle bars are secured to the outside surface of the sheets of metal of the casings by attaching one of the limbs of the angle bars to the outside surface of the sheets. The upper side ends of the sheets of metal are bent upwardly to the top of the angle bar that is secured along its edge in order to form a wide topped edge in the space between the two side casings into which the concrete mortar is poured, while the flat limb of the angle bar at the lower edge of the casing forms broad footings for the opposite side casings.

The pins 8 that gage the depth of the pouring mold and consequently of the thickness of the concrete castings are secured to the casings by right angled brackets 14., one end of which is riveted to the side of the projecting flange of the angle bars that registers opposite to the angle bars of the inner tube, and the opposite end of these brackets projects over the top edge of the flange of the bar, and in each of these ends an aperture is formed, in which the pins 8 below their heads fit loosely and turn freely. The. pin receiving holes of these brackets are each arranged in direct radial alinement with the threaded apertures in the inner tube. I illustrate four of these mold gaging screws, two at each end of each casing, but more can be used if desired. Each of these screws comprises a stem por tion 16, the inner end of which is reduced in diameter and is threaded to a shoulder 17, that bears against the surface of the tubular member of the form, while the threaded portion screws into the threaded The outer ends of these stems are provided with heads 18, that are arranged to receive a wrench or other turning means, and after the stems are screwed into the tube the casings are moved back on them until the brackets bear against the heads. Then the casings are set in this position by a set screw 19, that is threaded through the side of the bracket The i 14 and the flange of the angle bar, the end of which is pointed and extends into a circumferential groove 20, that is formed in the stem of each screw to receive it. These set screws lock the casings to the stems so that they cannot move either toward or away from the inner tubular member, and they also lock the stems so they cannot be turned out from the inner tube. By making screws of greater or of less length than those illustrated, the space between the casings and the inner tube can be increased or diminished as desired, and consequently the thickness of the concrete ring molded in the form can be changed to any thickness desired. These screws not only hold the two cooperating members of my form in such predetermined, separated and spaced relation as I desire for different kinds and characters of work, but they also rigidly truss and support the two members relative to each other, as they are secured rigidly to both members. Thus the set screws secure the casings to the stem,

and the threaded part of the stems when screwed tightly into the tubular member secures the stems securely to it. These stems positioned as illustrated, are all that is necessary to support the two members of my form to receive and hold the concrete mortar as it is poured into the space between them, for all of the general sizes of pipe covering and other work, and their use and trussing efiect in supporting these two members of my improved concrete molding form is available and an essential element of my invention. As for the general run of work, no other form or charac ter of supporting or trussing members is necessary to hold these cooperating parts oi my invention in proper operating relation to each other, but other trussing, stiffening and also reinforcing rods may be used around or below the inner tube in any practical manner desired.

When it is desired to mold into the 0011- crete reinforcing members such as rods, or net-ting, or wire lathing of any kind, one of the ends of the same can be secured to the entrance edges of the casings and they can be bent and carried down centrally through the space between the casings and the inner tube and can be secured in any suitable manner to the lower screws, and in the case of rods, they can be crossed from one corner of the casings to the other corner, as shown in Fig. :2, and any kind of reinforcing can be carried down and around the inner tube in the space around and below it, by curving the same. In Fig. 5, I illustrate a modification of the arrangement shown in Fig. 1, and other single inner tube construction. In this modification the concrete casting mold is arranged to make a concrete casting containing two pipe-like apertures instead of one as shown in Fig. 1.

Consequently the form is made wide enough to contain two inner tubes which are placed at a short distance apart and in horizontal alinement, and are secured together and are spaced at a predetermined distance part by a bolt and sleeve 20. The sleeve fits between the tubes and the bolt extends through the adjacent segments of the casing, and thus bolts these segments and the tubes together. The elements used are the same as in the single tube form, but to them it is necessary to add a spreader bar 21, at the top of the casings, which eXtends across thetop edges and is removably clamped by a yoke and clamping screw or by other means to the opposite top edge members of the casings, and also a horizontal casing connecting bolt 23 at the bottoms of the casings, which QX- tends through apertures in their bottom end portions and across between them and underneath the inner tubes. The supporting top spreader bar and the lower casing connecting bolt can be used on all of single forms if desired. Both of these tubes are collapsible and the side-casings are of substantial construction as the casings in the single tube form, as all portions of the form used for the single tubular pipe construction are available for use where additional inner tubular members are used, but the above additional mentioned elements are necessary and the same general construction can be applied to three or more inner tubular members of any form of cross section.

My invention is applicable to all kinds of tubular forms, and in Figs. (5, 7, and 8, the outlines of three diflerent tubular cross sections of inner tubes and their outer surrounding casings, are shown. The connections between the inner tubes and their outside casings are substantially the same. In Figs. 7 and 8 however, two hinges are used, one at each lower corner; otherwise these forms are similar to the round form shown in Fig. 1. The-operation of my improved concrete molding form is as follows: If a pipe-like or tubular apertured form of a concrete casting is to be molded, of any practical form of cross section, the hinged segments of the inner tube are first brought together against the segment a, so as to form a tubular member 1. The outside casings are then placed in position on the opposite sides of the inner tube and the screws are insertedin their apertures in the brackets of the casings and in the screws which locks the casings andthe inner tube in their proper operative relation to each other. The mold is then ready 13a to be poured with mortar concrete, which is poured down between the top ends of the side casings and it runs down between the inner tube and the outer casings and around and under the bottomof the inner tube, and the mortar is continuously poured into the space between the two members or the form until it is full of concrete to the top of the entrance of the casings. lVhile one of the forms is being filled with concrete another form is being set up and bolted to one of its ends, which is also filled as soon as the first form is filled. In this way several forms can be in the process of being filled and of setting while additional forms can be secured to the end or to the opposite ends of these in the process of being filled and in which the concrete is setting. Then those in which the concrete has set firmly enough to permit of it, are removed from the now molded concrete casting. This is accomplished by first loosening the set screws and removing the screws from the outer casings by unscrewing them from the inner tube, then drawing the casings directly back from the molded castings, which will leave the outside of the molded concrete casting exposed to view. Next remove the inner tube, which is accomplished by collapsing the same; the segment t is removed first. and it this segment did not fall into the interior of the inner tube at the time the screws were removed from it, a slight rapping against this segment with a hammer will cause it to fall into the interior of the tube, as there nothing to hold it between the segments and 3. Then having removed this segment l, draw or pry the top free ends of the two segments 2 and 3 together, and then it can be easily withdrawn lengthwise out of the hole in the concrete casting.

My improved concrete molding form is simple and can be readily and quickly up and then filled with concrete and then be taken down and be speedily set up again by unskilled workmen and without any danger of disa1"angement of the parts, and it provides a cheaply constructed and thoroughly practical concrete molding form.

My invention contemplates the use of any practical construction and arrangement of the threaded rod supporting brackets, and of any desired kind of stiffening rods or bars, and other members; and while I have illustrated and described the preferred construction and arrangementof my invention, I do not wish to be limited to it, as many changes might be made without de mrting from the spirit of my invention.

Having described my inventiomwvhat I claim as new and desire to secure by Letters Patent, is: 1

1..A concrete molding form, comprising an inner tubular member composed of three segment portions of the tubular member,

two of which are hinged together and the third is arranged to fit between the other two in such a manner as to form a substantially true circular tube, and two casing members arranged to partially surround the inner tube at a predetermined concrete mortar receiving space from said inner tu bular member, and screws arranged to secure said casings rigidly to said inner tube and at the same'time secure the unhinged segment of said inner tube to the said hinged segments.

2. In a concrete molding form, the combination of a knockdown multiple section collapsible inner tubular member arranged to be set up into operative concrete molding form and to be knocked down after the concrete casting has been made, and a pair of similarly aranged casings to partially surround the opposite sides of the said inner tube at a predetermined distance from it and having an open concrete receiving space between their entrance ends, the opposite ends of said casings being arranged to rest on the ground on a suitable form, and means including screws extending loosely through said casings and threaded to said multiple section collapsible inner tube, in such a manner as to releasably secure said sections together in tubular form, and means including a set screw and a groove in said screw for securing said screws against accidental movement from said inner tube or from said castings, whereby said casings are rigidly held at a predetermined distance from the said casings.

3. The combination of outer independent casings and their attaching screws provided with a head at one end and a shouldered threaded portion at their opposite ends, grooves in said screws, set screws arranged to be moved into and out of said grooves, a bracket supporting said screws below said heads, with the inner collapsible tube comprising two segment members hinged together at their lower ends, said hinge members comprising an operative eye and pin hinge arranged on the inside of said segments in such a manner that said segments will fold inwardly from a true circle to a collapsible circle, a separate segment of a size to make a true circle when inserted between the hinged segments, projecting ends on the side ends of said separate segment overlapping against the under sides of said hinged segments, and threaded apertures through said hinged segments and the overlapping ends of said separate segment adapted to receive the threaded ends of said screws, whereby said casings and also said inner tube are cooperatively secured at a predetermined dis tance apart to receive a supply of concrete mortar between them.

45. In a concrete molding form, the combileavea gap between them of predetermined width, a separate segment fitting in and filling said gap, and a surrounding housing for said inner tube positioned at a predetermined distance from said inner tube and provided with a concrete mortar entrance space between them above the said inner tube, said housing comprising independent side members comprising sheets of metal reinforced with angle bars secured to the sides of said sheets, and means including screws of a predetermined length arranged to secure said housings at a predetermined distance from said inner tube, and means including registering end members at the ends of said housings whereby two or more of said housing members may be detachably secured in end to end alinement.

The combination of an inner collapsible tube and partially surrounding casings, said casings comprising sheets of metal having straight lower portions adapted to rest on the ground or on a form, said straight portions extending below said tube a predetermined distance and extending from the ground up to the central portion of said inner tube, said sheet metal casings then curving up partially over the top of said inner tube and separated far enough apart above said tube to leave a concrete mortar pouring entrance to said inner tube between their upper ends, trussing members secured to the outside of said sheet metal casing members, said trussing members comprising angled bars, one flange of which projects from said sheet metal casings, said angled bars being extended around the sides and ends of said sheet metal casings, thereby forming a broad marginal edge entirely around them, and means including bolt or pin receiving apertures in the opposite end fianges of said sheet metal casing for securing two or more of said casings together in end to end alinement, and means including screws of predetermined length supported in said casings against lateral movement and extending to and threadedly secured to the hinged and separate segments of said inner tube for supporting said casings at a predetermined concrete molding distance from said inner tube.

6. In a concrete molding form, the combination of an inner tubular member comprising three segment members, two of which are hinged together at their lower meeting edges and the third is arranged to tit between the top edges of the other two,

angle bars secured to the inside of the said hinged members and angle bars secured to the interior of the said separate section and arranged to overlappingly rest on the similar members of the hinged sections, a threaded aperture extending through said overlapping members of said sections from the outside of said two hinged sections, and a pair of asing members arranged to surround the opposite sides of: said tubular member, comprising sheet iron or steel side members, and

a plurality oi angle bars secured to the outside of said side members, brackets secured to said casing members and screws extendin g loosely through said bracket and casings and havinga body portion of a length to hold said casings at the predetermined dis tance from the said inner tube to form a concrete casting of the desired thickness, said screws being arranged to be threaded into the registering threaded apertures of said overlapping inner tube segments, and also to thread into the surface of said hinged segments of said inner tube, a wrench re ceiving head on the ends of said screws outside of said brackets, a circumferential groove in each of said screws and a set screw threaded to said bracket and casings and extending into the grooves of each of said screws, whereby said screws determine and define the concrete mortar holding space between said inner tube and said casings and cooperatively lock and truss them rigidly to each other.

7. A concrete molding form for molding concrete tubes, comprising a collapsible 1U inner tube and outside casings, said inner tube made of curved segments of a circle and arranged to be set up into a true tubular form and to be collapsed so as to be readily removed from the concrete casting after it is molded, said outside casings being arranged to partially surround said inner tube and arranged at a suflicient distance apart at their upper ends to permit concrete mortar to be poured around said inner tube, said casings being independent from each other, and means including screws of a predetermined length extending through said casings and secured to the segments of said inner tube in such a manner as to secure them to gether, and arranged to hold said casings at a predetermined distance from said inner tube, and means whereby two or more of said concrete molding forms may be detachably secured together in end to end alinement.

8. The combination with outside casings, of a pair of inner tubular collapsible members arranged at a predetermined distance apart, means for securing said inner tubular members together in spaced relation, and securing screws secured to the said casing and to the said inner tubes.

9. The combination in a concrete molding form of a pair of inner tubes arranged side by side, casings partially surrounding the same, spacing sleeves and bolts extending through said sleeves and tubes for defining the space between said tubes, space defining screws arranged to be secured to said casings and to said inner tubes, and ar ranged to trussingly support said inner tubes and said casings in operative concrete mortar receiving relation to each other.

10. In a form of the character described, the combination of an inner collapsible tube, casing members spaced from said tube, and comprising upper portions which are concentric with the upper half of said tube, and terminate in Vertical portions which extend below the tube, an open space being left between the edges of the concentric portions, plates on said collapsible tube, having threaded apertures, screws which pass through said casing members, having reduced threaded ends which enter the thread ed apertures in said plates, and means for preventing baclnvard rotation of said screws, brace rods connecting said casing members below the inner tube, curved angle plate members secured to the tubes flush with their ends, and apertured angle plates on the ends of said casing members whereby a plurality of said casing members may be bolted together.

In testimony whereof I ailix my signature in presence of two witnesses.

ERVIN M. CAMP. l'Vitnesses G. Sancex'r ELLIOTT, ADELLA M. FowLE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C. 

